Project description:Complementary bottom-up MS/MS analyses contributed to complete a locus-resolved venom phenotype map for O. hannah, the world's longest venomous snake and a species of medical concern across its wide distribution range in forests from India through Southeast Asia. Its venom composition convincingly explains the main neurotoxic effects of human envenoming caused by king cobra bite. The integration of efficient chromatographic separation of the venom components, and locus-resolved toxin identification through top-down and bottom-up MS/MS-based species-specific database searching, promises a bright future to the field of venom research.
Project description:Capsicum frutescens is one of the chilli varieties, with erect, highly pungent fruits. This variety is used to prepare hot sauces, chilli concentrates, and oleoresin. Its fruits are also used in traditional Indian medicine to treat arthritis and zoster related pain management. Infection by Polyphagotarsonemus latus commonly called as the Broad mite in chilli, make the leaves turn coppery and dark, show symptoms of leaf curl and stunted growth that eventually results in low yield and economic loss. We carried out gel-free, labelled mass spectrometry-based quantitative proteomic analysis of leaves and apical meristems of healthy and infected plants. We identified a total of 5799 proteins, of which total of which, 1677 proteins found to dysregulated in infested plants.
Project description:Capsicum spp. (hot peppers) demonstrate a range of interesting bioactive properties spanning anti-inflammatory, antioxidant, and antimicrobial activities. While several species within the genus are known to produce antimicrobial peptides (AMPs), AMP sequence mining of genomic data indicates this space remains largely unexplored. Herein, in silico AMP predictions are paired with peptidomics to identify novel AMPs from the interspecific hybrid ghost pepper (Capsicum chinense x frutescens). AMP prediction algorithms reveal 115 putative AMPs within the Capsicum chinense genome of which 14 were identified in the aerial tissue peptidome. PepSAVI-MS, de novo sequencing, and complementary approaches were used to fully molecularly characterize two novel AMPs, CC-AMP1 and CC-AMP2, including elucidation of post-translational modifications and disulfide bond connectivity. Both CC-AMP1 and CC-AMP2 have little homology with known AMPs and exhibit low µM antimicrobial activity against gram-negative bacteria including Escherichia coli and Klebsiella pneumoniae. These findings demonstrate the complementary nature of peptidomics, bioactivity-guided discovery, and bioinformatics-based investigations to more fully characterize plant AMP profiles.
Project description:Antimicrobial peptides (AMPs) are compounds with a variety of bioactive properties. Especially promising are their antibacterial activities, often towards drug-resistant pathogens. Across different AMP sources, AMPs expressed within plants are relatively underexplored, with a limited number of plant AMP families identified. Recently, we identified the novel AMPs CC-AMP1 and CC-AMP2 in ghost pepper plants (Capsicum chinense x frutescens), exerting promising antibacterial activity and not classifying into any known plant AMP family. Herein, AMPs related to CC-AMP1 and CC-AMP2 were identified within both Capsicum annuum and Capsicum baccatum. Targeted MS/MS experiments were performed to determine peptide sequences, guided by in silico AMP sequence predictions.
Project description:Metaproteomic analysis of King Ghezo's tomb wall in Abomey (Benin), capital of the ancient kingdom of Dahomey. Without any a priori metaproteomics interpretation allowed identification of the proteins and their taxonomical origins, and thus archaeological reconstruction of voodoo rituals of consecration and maintenance of vitality.